 He joined the cast of the show on September 8, 2005, and made his final appearance on September 24, 2007.Parnell also provides the voice of Jefferson Twilight on Cartoon Network's "The Venture Bros." He also played the role of Master Chief Russ Jeter on the TNT show "The Last Ship".Before taking the role of Derek Frye, Parnell played Achilles in "Iphigeneia at Aulis", a play by Euripides translated and adapted by Kenneth Cavander at the Yale Repertory Theater in New Haven, Connecticut.